Insights into the Mechanism of Selective Removal of Heavy Metal Ions by the Pulsed/Direct Current Electrochemical Method.

Heavy metal pollution treatment in industrial wastewater is crucial for protecting biological and environmental safety. However, the highly efficient and selective removal of heavy metal ions from multiple cations in wastewater is a significant challenge. This work proposed a pulse electrochemical method with a low-/high-voltage periodic appearance to selectively recover heavy metal ions from complex wastewater. It exhibited a higher recovery efficiency for heavy metal ions (100% for Pb2+ and Cd2+, >98% for Mn2+) than other alkali and alkaline earth metal ions (Na+, Ca2+, and Mg2+ were kept below 3.6, 1.3, and 2.6%, respectively) in the multicomponent solution. The energy consumption was only 34-77% of that of the direct current electrodeposition method. The results of characterization and experiment unveil the mechanism that the low-/high-voltage periodic appearance can significantly suppress the water-splitting reaction and break the mass-transfer limitation between heavy metal ions and electrodes. In addition, the plant study demonstrates the feasibility of treated wastewater for agricultural use, further proving the high sustainability of the method. Therefore, it provides new insights into the selective recovery of heavy metals from industrial wastewater.

Engraving Polyamide Layers by In Situ Self-Etchable CaCO3 Nanoparticles Enhances Separation Properties and Antifouling Performance of Reverse Osmosis Membranes.

Nanovoids within a polyamide layer play an important role in the separation performance of thin-film composite (TFC) reverse osmosis (RO) membranes. To form more extensive nanovoids for enhanced performance, one commonly used method is to incorporate sacrificial nanofillers in the polyamide layer during the exothermic interfacial polymerization (IP) reaction, followed by some post-etching processes. However, these post-treatments could harm the membrane integrity, thereby leading to reduced selectivity. In this study, we applied in situ self-etchable sacrificial nanofillers by taking advantage of the strong acid and heat generated in IP. CaCO3 nanoparticles (nCaCO3) were used as the model nanofillers, which can be in situ etched by reacting with H+ to leave void nanostructures behind. This reaction can further degas CO2 nanobubbles assisted by heat in IP to form more nanovoids in the polyamide layer. These nanovoids can facilitate water transport by enlarging the effective surface filtration area of the polyamide and reducing hydraulic resistance to significantly enhance water permeance. The correlations between the nanovoid properties and membrane performance were systematically analyzed. We further demonstrate that the nCaCO3-tailored membrane can improve membrane antifouling propensity and rejections to boron and As(III) compared with the control. This study investigated a novel strategy of applying self-etchable gas precursors to engrave the polyamide layer for enhanced membrane performance, which provides new insights into the design and synthesis of TFC membranes.

Superhydrophobic Nanoparticles: An Efficiently Selective Adsorbent for Surfactant-Like Contaminants from Complex Wastewater Matrices.

Surfactant-like contaminants (SLCs) with distinctive amphiphilic structures have become a global concern in wastewater due to their toxicity and persistency. Despite extensive efforts, achieving efficient and selective SLCs removal remains challenging because of their wide range of molecular weights and complex functional group compositions. Superhydrophobic nanoparticles can potentially tackle this challenge by targeting the long oleophilic chains of SLCs. However, conventional contact angle measurements hinder hydrophobicity characterization and corresponding selectivity research because of the powder morphology of nanoparticles. Herein, the authors offered information regarding the distribution of water molecular probes in surfaces and proposed a quantitative characterization approach based on low-field nuclear magnetic resonance. Through synthesizing superhydrophobic and hydrophilic polydopamine nanospheres with similar morphologies, the selective adsorption potential of superhydrophobic nanoparticles for SLCs is systematically demonstrated. As revealed by the interaction mechanisms, the superhydrophobic surface of nanospheres increased its affinity and selectivity for SLCs adsorption by enhancing hydrophobic interactions. Superhydrophobic modification achieved ten times the adsorption capacity of sodium dodecyl benzene sulfonate, an exemplified surfactant, compared with pristine nanoparticles. By regulated self-polymerization, the superhydrophobic nanospheres are coated onto the surface of a 3D sponge and enable efficient selective SLCs adsorption from highly polluted leachate matrices with long-term stability and reusability.

The Adsorption Behaviors and Mechanisms of Humic Substances by Thermally Oxidized Graphitic Carbon Nitride.

Thermal oxidation is efficient for enhancing the photocatalysis performance of graphitic carbon nitride (g-C3N4), while its effect on adsorption performance has not been fully studied, which is crucial to the application of g-C3N4 as adsorbents and photocatalysts. In this study, thermal oxidation was used to prepare sheet-like g-C3N4 (TCN), and its application for adsorption of humic acids (HA) and fulvic acids (FA) was evaluated. The results showed that thermal oxidation clearly affected the properties of TCN. After thermal oxidation, the adsorption performance of TCN was enhanced significantly, and the adsorption amount of HA increased from 63.23 (the bulk g-C3N4) to 145.35 mg/g [TCN prepared at 600 °C (TCN-600)]. Based on fitting results using the Sips model, the maximum adsorption amounts of TCN-600 for HA and FA were 327.88 and 213.58 mg/g, respectively. The adsorption for HA and FA was markedly affected by pH, alkaline, and alkaline earth metals due to electrostatic interactions. The major adsorption mechanisms included electrostatic interactions, π-π interactions, hydrogen bonding, along with a special pH-dependent conformation (for HA). These findings implied that TCN prepared from environmental-friendly thermal oxidation showed promising prospects for humic substances (HSs) adsorption in natural water and wastewater.

Identification of key surfactant in municipal solid waste leachate foaming and its influence mechanism.

Serious foaming problems and the excessive consumption of defoamer have undoubtedly become one of the most critical problems that hinder municipal solid waste (MSW) leachate treatment efficiency and industry development. Since there is limited research penetrating the foaming mechanism and identification of the key surfactants, current defoaming and surfactant removal techniques lack pertinence and orientation. In this study, a foaming characterization device was developed and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS/MS) was optimized to accurately identify the key surfactants affecting leachate foaming and offer a glimpse into their interaction mechanisms. This study collected leachate samples from 9 typical landfills and waste-to-energy facilities of various waste compositions, climatic conditions, ages, and geographical locations. The foaming problem of leachate was mainly centered on raw leachate and nanofiltration membrane concentrate (NFC). Fresh leachate performed with relatively low foaming capacity and foam stability, associated with low surfactant concentration. The pH value of the system was positively correlated with the concentration of anionic surfactants, indicating significant impacts on surfactant release in MSW. Since the distribution characteristics of linear alkylbenzene sulfonate (LAS) in leachate were consistent with the variety of foaming performances, LAS proved to be an indispensable surfactant in the leachate involved in this study, and its content proportion escalated to 92.87% in aged leachate.

Rapid Regeneration of a Neoartery with Elastic Lamellae.

Native arteries contain a distinctive intima-media composed of organized elastin and an adventitia containing mature collagen fibrils. In contrast, implanted biodegradable small-diameter vascular grafts do not present spatially regenerated, organized elastin. The elastin-containing structures within the intima-media region encompass the elastic lamellae (EL) and internal elastic lamina (IEL) and are crucial for normal arterial function. Here, the development of a novel electrospun small-diameter vascular graft that facilitates de novo formation of a structurally appropriate elastin-containing intima-media region following implantation is described. The graft comprises a non-porous microstructure characterized by tropoelastin fibers that are embedded in a PGS matrix. After implantation in mouse abdominal aorta, the graft develops distinct cell and extracellular matrix profiles that approximate the native adventitia and intima-media by 8 weeks. Within the newly formed intima-media region there are circumferentially aligned smooth muscle cell layers that alternate with multiple EL similar to that found in the arterial wall. By 8 months, the developed adventitia region contains mature collagen fibrils and the neoartery presents a distinct IEL with thickness comparable to that in mouse abdominal aorta. It is proposed that this new class of material can generate the critically required, organized elastin needed for arterial regeneration.

Phosphorylation modification on functional and structural properties of fish gelatin: The effects of phosphate contents.

The gel, rheological and structural properties of fish gelatin (FG) were investigated through phosphorylation with different ratios of sodium pyrophosphate (TSPP) (FG:TSPP = 40:0, 40:1, 40:2, 40:4, and 40:6). It showed that phosphorylation modification significantly increased gel strength, textural properties, emulsification, and emulsification stability of FG. The surface hydrophobicity and intrinsic fluorescence of phosphorylated FG were also significantly increased. Rheological results revealed that the apparent viscosity, melt/gel points, and gel strength of FG were increased by phosphorylation with TSPP, but shortened the gelation time. Low field nuclear magnetic resonance (LF-NMR) showed that phosphorylation reduced mobility of water in FG. FTIR results indicated that phosphorylation increased the ß-sheet/ß-turn contents but reduced the random coil contents. This study might provide a new guideline for the exploration of TSPP phosphorylation increased the functional properties of FG.

Effects of light and water disturbance on the growth of Microcystis aeruginosa and the release of algal toxins.

Eutrophication of water constitutes a serious threat to global water quality. Light intensity and water disturbance are important factors affecting the growth of algae and the release of algal toxins. In this study, algal growth indicators, algal enzyme systems, and algal toxin release in Microcystis aeruginosa under different light intensities and water disturbances were determined. The results showed that 2500 lx and 120 rpm were the optimal conditions for the growth of M. aeruginosa. The growth of algal cells was inhibited by high light intensity and high water disturbance. However, the optimal conditions for algal growth were not favorable conditions for the release of algal toxin. The highest concentration of microcystin-LR (MC-LR), observed at 4500 lx and 80 rpm, was 198.1 µg/L, whereas the highest single cell toxin production reached up to 10.49 × 10-9  µg/cell at 7000 lx and 120 rpm. Redundancy analysis results showed that the concentration of MC-LR was positively correlated with algal cell density and antioxidant enzyme activities (superoxide dismutase, catalase, peroxidase, and malondialdehyde [MDA]) and negatively correlated with the total nitrogen and total phosphorus consumption rates and MDA. Single cell toxin production was negatively correlated with algal cell density and antioxidant enzyme activity but positively correlated with MDA content. PRACTITIONER POINTS: There was an optimal water disturbance condition for algae growth affected by the light intensity. Optimal conditions for algae cell growth are not necessarily the optimal conditions for algal toxin release. Enzyme indicators have correlation with the release of algae toxins and the growth of algae cells.

Life Cycle Assessment of Leachate Treatment Strategies.

Increasingly stringent regulations for leachate discharge call for leachate treatment plants (LTPs) to increase their treatment capacity by adopting membrane treatment processes to remove nitrogen and organics beyond conventional biological treatment processes. This study developed four common treatment strategies based on the existing operation and construction conditions of seven representative LTPs in China. We evaluated the LTPs' environmental impacts using life cycle assessment (LCA) following the International Organization for Standardization (ISO 14040 and ISO 14044). Compared with conventional secondary treatment processes, implementing high-level technologies to meet the strict standards could reduce an average of 59% of the eutrophication potential while increasing other environmental impacts resulting from both direct and indirect emissions by an average of 146%. We propose advanced technologies that integrate both midpoint and endpoint LCA results to meet stringent standards in areas sensitive to eutrophication.

Insights into Adsorption of Humic Substances on Graphitic Carbon Nitride.

Graphitic carbon nitride (CN) has been widely used in environmental pollution remediation. However, the adsorption of organic compounds on CNs, which has practical significance for the environmental application of CNs, is poorly understood. For the first time, this study systematically investigated the adsorption behaviors and mechanisms of humic substances (HSs), i.e., humic acid (HA) and fulvic acid (FA), on CNs derived from four typical precursors. Intriguingly, CN derived from urea (CN-U) showed a great capacity for HS adsorption due to its porous structure and large surface area, with maximum adsorption amounts of 73.24 and 51.62 mgC/g for HA and FA, respectively. The formation, influencing factors, and relative contributions of multiple interactions to HS adsorption on CNs were thoroughly elucidated. HS adsorption on CNs was mainly mediated by electrostatic interactions, π-π interactions, and H-bonding. The dominance of electrostatic interactions resulted in HS adsorption being highly dependent on pH and ionic strength. HS components with high aromaticity and high molecular weight were preferentially adsorbed due to π-π interactions. These multiple interactions were largely affected by amino groups and tri-s-triazine units of CNs, as well as the moieties of aromatic rings and oxygen-containing groups of HSs.

An autophagy-related prognostic signature associated with immune microenvironment features of uveal melanoma.

Autophagy is involved in cancer initiation and progression but its role in uveal melanoma (UM) was rarely investigated. Herein, we built an autophagy-related gene (ARG) risk model of UM patients by univariate Cox regression and least absolute shrinkage and selection operator (Lasso) regression model and filtrated out nine prognostic ARGs in The Cancer Genome Atlas (TCGA) cohort. Survival and Receiver Operating Characteristic (ROC) Curve analysis in the TCGA and other four independent UM cohorts (GSE22138, GSE27831, GSE44295 and GSE84976) proved that the ARG-signature possessed robust and steady prognosis predictive ability. We calculated risk scores for patients included in our study and patients with higher risk scores showed worse clinical outcomes. We found the expressions of the nine ARGs were significantly associated with clinical and molecular features (including risk score) and overall survival (OS) of UM patients. Furthermore, we utilized univariate and multivariate Cox regression analyses to determine the independent prognostic ability of the ARG-signature. Functional enrichment analysis showed the ARG-signature was correlated with several immune-related processes and pathways like T-cell activation and T-cell receptor signaling pathway. Gene set enrichment analysis (GSEA) found tumor hallmarks including angiogenesis, IL6-JAK-STAT3-signaling, reactive oxygen species pathway and oxidative phosphorylation were enriched in high-risk UM patients. Finally, infiltrations of several immune cells and immune-related scores were found significantly associated with the ARG-signature. In conclusion, the ARG-signature might be a strong predictor for evaluating the prognosis and immune infiltration of UM patients.

Responses to crizotinib and cabozantinib in patient with lung adenocarcinoma harboring mesenchymal-epithelial transition factor exon 14 skipping mutation: A case report.

RATIONALE: Lung cancer is a leading cause of cancer-related mortality worldwide. Currently, targeted therapy has proved highly efficient in the treatment of advanced non-small cell lung cancer (NSCLC). Mesenchymal-epithelial transition factor (MET) is considered a validated molecular target in NSCLC. Given the low incidence of MET exon 14 skipping mutation, the planning of precision treatment for patients is a clinical problem that needs to be solved. In this report, we present a MET-positive case that benefited from crizotinib and cabozantinib treatment. PATIENT CONCERNS: A 77-year-old patient was diagnosed with lung adenocarcinoma in our hospital. Positron emission tomography-computed tomography (PET-CT) showed a right upper lobe mass (58 × 56 mm, SUVmax 15.6), right hilar enlarged lymph nodes, and multiple bone and left adrenal metastases (c-T3N1M1c). DIAGNOSES: MET exon 14 mutation (exon14, c.2888-1G>C) was examined using the lung puncture sample by next generation sequencing. Therefore, the patient was diagnosed with late-stage lung adenocarcinoma with MET exon14 skipping gene mutation. INTERVENTIONS: Crizotinib was given as the first-line treatment from August 2019. Considering the resistance of crizotinib, cabozantinib was given for second-line treatment. OUTCOMES: Crizotinib was administered (250 mg bid) for 8 months, and her disease achieved partial regression (PR) and progression-free survival (PFS), which lasted for 8 months. The patient also reached PR after the second-line treatment with cabozantinib, and is currently under follow-up, with an overall survival (OS) of >12 months. LESSONS: As MET exon 14 skipping mutation is rare in clinical practices, MET-TKIs (tyrosine kinase inhibitors) treatment can boost curative effects and improve prognosis of patients with advanced lung adenocarcinoma. This case report supports a rationale for the treatment of lung adenocarcinoma patients with a MET exon 14 skipping mutation and provides alternative treatment options for these types of NSCLC patients.

COVID-19 and energy: Influence mechanisms and research methodologies.

Considering the important role of energy in modern society, it is imperative to study the current situation and future development of energy under the influence of COVID-19. This paper identifies the current research hotspots, proposes future research directions accordingly, and summarizes the methodologies via a bibliometric analysis. Five research hotspots include COVID-19 and the changes of energy consumption, COVID-19 and the fluctuation of the energy market, COVID-19 and the development of renewable energy, COVID-19 and climate impacts caused by energy consumption, and COVID-19 and the energy policy. According to the influence mechanism of COVID-19 on each hotspot, the pandemic has exerted short-term influencs on energy consumption, energy price, and air pollution. Meanwhile, the pandemic could have a far-reaching impact on the renewable energy sector, climate, and energy policy. In addition, the main methodologies are reviewed, revealing that regression analysis and scenario analysis are commonly used as the quantitative and qualitative methods, respectively. Moreover, given the nonlinear relations between the pandemic and energy, an artificial neural networks model is used to enhance the prediction efficiency of energy demand and price. Finally, policy implications for obtaining clean, low-carbon, safe, and efficient energy in the context of COVID-19 are proposed.

Effect of submerged combustion evaporation on Cd complexation potential of organic matter in municipal solid waste landfill leachate.

Despite the strong ability for complexation of heavy metals, a high amount of humic substances (HS) is always contained in membrane retentate from municipal solid waste landfill leachates treatment processes. Submerged Combustion Evaporation (SCE) can be used to effectively concentrate the membrane retentate. However, the impact of the SCE treatment on HS complexation capacity is still unclear. Since cadmium (Cd) plays a vital role in the pollution of soil and food, this study investigated the influence of the SCE treatment on the Cd complexation potential of leachate HS. Specific effects and complexation properties on Cd complexation of leachate HS before and after the SCE treatment were demonstrated using the Non-Ideal Competitive Adsorption model. The results showed that the Cd complexation capacity of carboxyl sites increased from 3.76 to 4.65 mol/kg-Total Organic Carbon (TOC) after the SCE treatment, which agreed with the stoichiometric number of proton binding sites. Moreover, characterization results indicated that SCE increased the affinity of HS for Cd by enhancing the overall aromaticity of HS (E2:E4 from 9.8 to 9.3), dominantly due to the humic acid contribution. By modeling the practical Cd remediation scenarios, the enhanced Cd complexation performance of HS after SCE treatment was observed even at low pH values (pH = 5) or insufficient TOC content (TOC = 50 mg/L).

Traditional Chinese medicine on treating active rheumatoid arthritis: A protocol for systematic review and meta-analysis.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease associated with progressive joint damage and disability. There is a lack of effective methods in the treatment of RA currently. Many clinical trials have proved that traditional Chinese medicine (TCM) has obvious advantages in the treatment of RA. In this systematic review, we intend to evaluate the efficacy and safety of TCM for active RA. METHODS: We will search PubMed, the Cochrane Library, Embase, Web of Science, the Chinese National Knowledge Infrastructure Database, Wanfang Data, and Chinese Science and Technology Periodical Database. Simultaneously we will retrieval relevant meeting minutes, eligible research reference lists, symposium abstracts, and grey literatures. Included criteria are randomized controlled trials (RCTs) about TCM for active RA to assess its efficacy and safety. We will use the Revman 5.3 and Stata 13.0 software for data synthesis, sensitivity analysis, meta regression, subgroup analysis, and risk of bias assessment. The Grading of Recommendations Assessment, Development, and Evaluation standard will be used to evaluate the quality of evidence. RESULTS: This systematic review will provide a synthesis of TCM for patients with active RA from various evaluation aspects including tender joint count, swollen joint count, RF, CRP, ESR, DAS28, TCM syndrome evaluation criteria, and adverse events. CONCLUSION: The systematic review will provide evidence to assess the efficacy and safety of TCM in the treatment of patients with active RA. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019146726.

Response of the Bacterial Community and Antibiotic Resistance in Overnight Stagnant Water from a Municipal Pipeline.

Although drinking water safety has raised considerable concern, to date, the hidden health risks in newly released overnight water from a municipal pipeline have seldom received attention. In this study, bacterial community composition and the response of antibiotic-resistant bacteria (ARB) to ciprofloxacin, azithromycin, tetracycline, penicillin, and cephalosporin in overnight stagnant water were analyzed. With increases in heterotrophic bacteria plate count (HPC) during water stagnation, the numbers of ARB and the ARB/HPC ratios for the five antibiotics in resident water were observed to increase, which illustrated that the prevalence of ARB rose in the pipe network water during stagnation time (ST). Furthermore, during water stagnation for 12 h, an increase in bacteria related to fermentation was also observed. When the ST rose to 48 h, the fermentation bacteria become non-significant, and this was related to the exchange of pipe network water during daytime stagnation within the 48-h period. The antibiotic resistance index (ARI) showed that tetracycline had the highest resistance level in fresh water, and then decreased during water stagnation. When ST increased to 12 h, all ARI values of the five antibiotics were low, which was associated with changes in parameters during water retention and reduced resistance during short-term stagnation. When the ST increased to 24 and 48 h, the resistance to most antibiotics (except for tetracycline) increased, which showed that increasing antibiotic resistance is caused by the formation of biofilms in the pipeline during water stagnation.

Membrane Stabilization of Poly(ethylene glycol)-b-polypeptide-g-trehalose Assists Cryopreservation of Red Blood Cells.

As alternative cryoprotectants of conventional organic glycerol, biocompatible synthetic glycopeptides that can assist cryopreservation of red blood cells (RBCs) are proposed in this study. A series of glycopeptides are synthesized via ring-opening polymerization of N-carboxyanhydrides of lysine, aspartic acid, and phenylalanine initiated by poly(ethylene glycol)-NH2 and followed by chemical tethering carboxylated trehalose to the pendant amino moieties. The synthetic glycopeptides demonstrate distinguished features of low cytotoxicity, low hemolysis, and cell membrane stabilization. The specifically designed glycopeptides enhance cryosurvival recovery of sheep RBCs up to 87.3 ± 0.3% at pH 6.0 and 86.5 ± 0.3% at pH 7.4 together with trehalose during cryopreservation. The synergistic cryopreservation of RBCs is achieved via membrane stabilization of the glycopeptide and ice recrystallization inhibition of trehalose during freezing and thawing. Molecular dynamics simulation indicates that the glycopeptides enhance membrane stabilization at -196 °C by tuning water diffusion. This work provides a potential option of highly efficient and glycerol-free RBC cryopreservation by combination of synthetic glycopeptides and trehalose, which would inspire design and utilization of different mechanisms for the effective cryopreservation of cells or tissues.